The Cultivation of New Zealand Plants
Chapter IX. — Ferns for the Open Garden
Ferns for the Open Garden
Photo. C. E. Foweraker
Fig. 21. Rockery in suburbs of Christchurch planted with indigenous plants; in centre is the Spaniard (Aciphylla Colensoi).
Photo. C. E. Foweraker
Fig. 22. Myosotis uniflora, a forget-me-not of the cushion-form, growing on the stony bed of the River Cass. Canterbury.
The number of species of ferns occurring wild in New Zealand is one hundred and forty-four; enough surely, but less than many would expect. By far the greater part are forest plants, yet there is hardly any position, wet or dry, which does not possess its ferns, while two ascend to 6,000 feet at least. In the forest different ferns live in different positions according to the degree of shade, moisture in the ground, and so on. A knowledge of such matters is of great importance in the selection of ferns for the garden. It is also necessary to note what ferns remain in good condition after the forest has been felled, and their relation to sun and shade altogether changed. Thus the fern-grower can find out a good deal from simple observations in the locality of his garden, as to which are likely to succeed, and in what situation they should be grown.
As in the case of New Zealand plants in general, the geographical position of the garden is the deciding factor as to what class of ferns can, or cannot, be grown; indeed it speaks even more emphatically than for most other plants. Where the number of rainy days is so great that ferns are a common feature of any roadside, taking the place of grass, the capabilities of a garden in that page 104locality, for fern-culture, are at a maximum. To put it more widely, where the climate favours forest, fern-culture in the open is simple; but, where it favours tussock-grassland, it is far more difficult. In the former case, any shady part of the garden, other factors being suitable, should grow ferns; in the latter, the essential conditions for their well-being—shade, moisture, shelter—must be supplied.
This providing the above essentials is usually considered an artificial matter, a structure—it may be very ugly—called a "Fernery" being erected. Now, without anything of the kind, a good deal can be done, and something not unlike the interior of a forest be brought into being with its tree-ferns and other species, large and small.
A natural fernery of this kind was, many years ago, a most pleasing feature of the Christchurch Botanic Garden. The shade was provided by elms, other deciduous trees, and Nothofagus Solandri; these together with laurels and certain evergreens gave the shelter, and a water-pipe from an artesian well such additional moisture as might, from time to time, be necessary. But the point to note is, that the whole arrangement was natural. There were apparently no shade-trees or breakwinds, planted as such; rather did it look as if a certain part of the garden had been suitable for ferns, and they had come of their own accord; the only artificial portion was the inconspicuous water-pipe. There are hundreds of similar places suited for ferns in the gardens—public and private—of New Zealand, and, except in the dry districts, watering would be unnecessary, and even there the exception, not the rule.
In many places, once forest-clad, there are properties fortunate enough to have on them a remnant page 105of the original bush in which there will be more or less ferns. But, how seldom is the splendid advantage taken of introducing into such all the ferns of other parts of New Zealand which would thrive there. Frequently the bush is in a gully; if so, what artificial fernery could compete for beauty with such, when naturally planted?
Any gully may be quickly made suitable for ferns by planting rapid-growing trees on its sides; or, a suitable spot may be made by excavation, the soil being heaped up on either side. Inequalities, or hollows in the ground, may be taken advantage of.
Many gardens are too small for the planting of trees for shade purposes. But there is usually the shady side of a fence, of some outbuilding, or of the house itself, where many ferns will grow well, and the smaller the collection the more easy to water it occasionally.
In the warmer parts of New Zealand tree-ferns are used to a considerable extent for garden decoration, but not nearly so much as their beauty and effect warrant. It is surprising how little shade they require, so long as their base is protected from the sun (see Fig. 4). The best is the mamaku (Cyathea medullaris), but the ponga (C. dealbata) is rather more hardy. New Plymouth probably surpasses any other town in the extent to which tree-ferns are used.
The shade-requirements of ferns appear to form the best basis for a practical garden classification. But what follows must be used for comparative purposes only, since the necessary degree of shade for any fern, as already pointed out, differs in different localities.
No descriptions are given. The leaves of ferns are too complex in form to allow of a useful brief page 106description. However, photographs of all the species are to be seen in H. B. Dobbie's, "New Zealand Ferns," and to this book readers are referred.
Class 1.—Ferns requiring no shade in dry districts.
Blechnum (Lomaria) penna marina, (vh.); Cheilanthes Sieberi, (vh.), alpine-garden, dry ground; Doodia media, (hh.); Histiopteris (Pteris) incisa, (vh.); Hypolepis millefolium, (vh.); Lindsaya linearis, (vh.), grows in bogs; Notochlaena distans, (vh.); Paesia (Pteris) scaberula, (vh.), will grow in full sunshine in Christchurch.
Class 2.—Ferns requiring only the minimum amount of shade.
Asplenium bulbiferum, (vh.), there are many forms differing somewhat in their shade-requirements; A. flabellifolium, (vh.); A. flaccidum, (vh.), there are many forms; A. Hookerianum, (vh.); A. lucidum, (vh.), A. oblusatum and its allies, (vh.); Blechnum (Lomaria) Banksii, (vh.); B. capense (vh.) grows under many conditions. and changes its form greatly according to habitat; B. (L.) durum, (vh.); Cyathea dealbata (ponga, silver tree-fern, vh.); C. medullaris (mamaku, black tree-fern. h.); Cyclophorus (Polypodium) serpens (vh.) comes of its own accord in the wetter districts on rough-barked, exotic trees, e.g., Cupressus macrocarpa and elderberry (Sambucus niger); Dicksonia fibrosa, (vh); D. squarrosa wheki, vh.); Dryopteris (Polypodium) punctata, (vh.); Gleichenia circinata. (vh.); G. dicarpa, (vh.), these last two difficult to establish from wild plants; Hypolepis distans, (h.); H. tenuifolia, (vh.); Loxsoma Cunninghamii, (hh.); Pellaea falcata, (vh.); P. rotundifolia, (vh.); Polypodium diversifolium (Billardieri of all New Zealand books on page 107ferns), (vh.); Polystichum (Aspidium) Richardi, (vh.); P. vestitum (A. aculeatum var. vestitum), (vh.); Todaea barbara, (hh.).
Class 3.—Ferns requiring a moderate amount of shade.
Adiantum aethiopicum, (h.); A. affine, (vh.); A. fulvum, (h.); A. hispidulum, (hh.); Alsophila Colensoi (vh.) has its trunk mostly underground; Blechnum (Lomaria) discolor, (vh.); B. (L.) filiforme, (hh.); B. (L.) Fraseri, (hh.); B. (L.) lanceolatum, (vh.); B. (L.) vulcanicum, (vh.); Dicksonia lanata, (h.); Dryopteris (Nephrodium) glabella, (vh.); D. (N.) hispida, (vh.) D. (N.) velutina, (h.); Gleichenia Cunninghamii (umbrella-fern, vh.), difficult to establish; Hemitelia Smithii, (vh.); Leptolepia (Davallia) novae-zelandiae, (vh.); Lindsaya cuneata (trichomanoides), (vh.); Polypodium dictyopteris (Cunninghamii), (hh.); P. novae-zelandiae, (vh.); P. pustulatum, (h.); Polystichum adiantiforme (capense), (vh.); Pteris macilenta, (hh.); P. tremula, (hh.).
Class 4.—Ferns requiring a considerable amount of shade.
Adiantum formosum, (hh.); Asplenium Colensoi, (vh.); A. Richardi, (vh.); A. umbrosum, (hh.); Blechnum (Lomaria) fluviatile, (vh.); B. (L.) Pattersoni, (vh.), grows in drip of water or extremely wet ground; Cystopteris novae-zealandiae (fragilis of New Zealand authors—vh.); Dryopteris (Nephrodium) decomposita (h.); D. (Polypodium) pennigera, (vh.); Gleichenia flabellata, (hh.), difficult to establish: Leptopteris (Todaea) hymenophylloides, (vh.); Lindsaya viridis, (h.); page 108Lygodium articulatum, (hh.); Marattia fraxinea (para, king-fern, hh.).
For the treatment of the filmy ferns see Chapter X.